检索结果-南通市图书馆

distortion-aware beamforming design for multi-beam satellite communications with nonlinear power amplifiers

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第6期67卷 359-369页

作者： Xiang XIAO Li YOU Kezhi WANG Xiqi GAO National Mobile Communications research Laboratory Southeast University Purple Mountain laboratories department of Computer Science Brunel University London

Hardware components can cause different impairments, including power amplifier(PA) nonlinearities, which inevitably impact the system performance of satellite communications(SATCOM). In this work, we consider a multi-beam SATCOM downlink system and investigate the distortion-aware beamforming scheme with the characteristics of PA non-linearities. Notably, we aim to maximize the resource efficiency(rE), defined as the weighted sum of energy efficiency(EE) with spectral efficiency(SE), to obtain a flexible EE-SE tradeoff while accounting for the characteristics of PA distortion and the total power *** that the optimization objective is a sum of ratios and the high non-convexity involved in constraints,we propose an efficient approach that exploits the quadratic transformation, the Lagrange multiplier method,and the gradient ascent approach to handle this issue. Simulation results demonstrate the effectiveness of the distortion-aware beamforming approach in achieving the EE-SE tradeoff and exhibit a substantial rE performance gain over the conventional approach with ideal linear PAs assumed at the satellite transmitters.

关键词： multi-beam satellite communications nonlinear power amplifier energy and spectral efficiency tradeoff resource efficiency robust beamforming

同方期刊数据库

Mitigating set-stuck failure in 3d phase change memory: substituting square pulses with surge pulses

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第5期67卷 295-301页

作者： Ninghua LI Wang CAI Jun XIANG Hao TONG Weiming CHENG Xiangshui MIAO School of Integrated Circuits Huazhong University of Science and Technology Hubei Yangtze Memory laboratories Hubei Institute of Measurement and Testing Technology

In the devices that integrate phase change memory(PCM) and ovonic threshold switching(OTS),the OTS threshold voltage often surpasses the rESET operation voltage of PCM. The conventional application of square pulses hinders the successful completion of the SET operation in these integrated devices. To address this challenge, a novel pulse called the surge pulse is introduced, which comprises a high amplitude pulse for OTS activation and a low amplitude pulse for PCM operation. By employing COMSOL simulation,the operational effectiveness of both square pulses and surge pulses is validated. Test results reveal that using a square pulse to operate the integrated device accelerates the occurrence of SET-stuck failure(SSF).In contrast, the surge pulse enables the integrated device to operate for at least 1000 cycles while preserving the essential cyclic characteristics. Additionally, an investigation into the overshoot component of the surge pulse is conducted, revealing that an increase in overshoot amplitude and pulse width also accelerates the emergence of SSF. By applying the theory of ion migration induced by the electric field, the root cause of SSF in integrated devices is explained, and the accuracy of the theory is validated through the application of a reverse pulse. In summary, this study elucidates the rationality of replacing the square pulse with a surge pulse, presenting a superior approach for operating PCM and OTS integrated devices.

关键词： surge pulse phase change memory (PCM) integration SET-stuck failure (SSF) square pulse

High spectral efficiency 4-mode 400-km transmission using hybrid probabilistically and geometrically shaped 128QAM

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第5期67卷 1628-1630页

作者： dING JunJie YU JianJun WANG Chen LONG JianYu ZHU Min ZHANG Jiao Pervasive Communication research Center Purple Mountain LaboratoriesNanjing 211111China Key Laboratory for Information Science of Electromagnetic Waves(MoE) Fudan UniversityShanghai 200433China

Wavelength division multiplexing(WdM)and space division multiplexing(SdM)based on few-mode fiber(FMF)and multi-core fiber(MCF)have been vigorously developed to increase the transmission capacity of optical communication networks[1–5].However,the mode crosstalk generated in the mode division multiplexing(MdM)system causes the correlation between different mode signals,which seriously damages the transmission ***,an effective multiple-input-multiple-output(MIMO)time domain or frequency domain equalizer should be used to eliminate the crosstalk between different mode signals.

关键词： crosstalk fiber multiplexing

Magnetic Nonreciprocity in a Hybrid device of Asymmetric Artificial Spin-Ice-Superconductors

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2024年第6期41卷 119-127页

作者：李冲黄培源王晨光李浩杰吕阳阳岳文诚袁子雄李甜雨涂学凑陶涛董思宁何亮贾小氢孙国柱康琳王华兵吴培亨王永磊 research Institute of Superconductor Electronics Nanjing UniversityNanjing 210093China Purple Mountain laboratories Nanjing 211111China National Key Laboratory of Spintronics Nanjing UniversitySuzhou 215163China

Controlling the size and distribution of potential barriers within a medium of interacting particles can unveil unique collective behaviors and innovative *** introduce a unique superconducting hybrid device using a novel artificial spin ice structure composed of asymmetric *** structure forms a distinctive superconducting pinning potential that steers unconventional motion of superconducting vortices,thereby inducing a magnetic nonreciprocal effect,in contrast to the electric nonreciprocal effect commonly observed in superconducting ***,the polarity of the magnetic nonreciprocity is in situ reversible through the tunable magnetic patterns of artificial spin *** findings demonstrate that artificial spin ice not only precisely modulates superconducting characteristics but also opens the door to novel functionalities,offering a groundbreaking paradigm for superconducting electronics.

关键词： artificial collective reciprocal

OFdMA-Based Unsourced random Access in LEO Satellite Internet of Things

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第1期21卷 13-23页

作者： Jiaqi Fang Gangle Sun Wenjin Wang Li You rui ding National Mobile Communications research Laboratory Southeast UniversityNanjing 210096China Purple Mountain laboratories Nanjing 211100China Institute of Telecommunication Satellite CASTBeijing 100094China

This paper investigates the low earth orbit(LEO)satellite-enabled coded compressed sensing(CCS)unsourced random access(UrA)in orthogonal frequency division multiple access(OFdMA)framework,where a massive uniform planar array(UPA)is equipped on the *** LEO satellite communications,unavoidable timing and frequency offsets cause phase shifts in the transmitted signals,substantially diminishing the decoding performance of current terrestrial CCS UrA *** cope with this issue,we expand the inner codebook with predefined timing and frequency offsets and formulate the inner decoding as a tractable compressed sensing(CS)***,we leverage the inherent sparsity of the UPA-equipped LEO satellite angular domain channels,thereby enabling the outer decoder to support more active ***,the outputs of the outer decoder are used to reduce the search space of the inner decoder,which cuts down the computational complexity and accelerates the convergence of the inner *** results verify the effectiveness of the proposed scheme.

关键词： LEO OFdMA satellite unsourced random access UPA

Intelligent Control Plane Techniques for Next Generation Optical Switching Networks

在线全文

学校读者我要写书评

暂无评论

China Communications 2012年第8期9卷 29-39页

作者： Takehiro Tsuritani Liu Lei kddi r&d laboratories Inc. 2-1-10 Ohara Fujimino Saitama 356-8502 Japan

For the next generation optical switching networks, the intelligent control plane is a key enabling technique. In this paper, we review our recent research activities related to Generalized Multi-Protocol Label Switching (GMPLS) and Open Flow-based control planes for both Wave length Switched Optical Networks (WSON) and Elastic Optical Networks (EON).

关键词：控制平面技术光交换网络智能通用多协议标签交换 GMPLS 使能技术波长交换研究活动

A Correlation-Based Stochastic Model for Massive MIMO Channel

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第1期21卷 175-187页

作者： Yang Liu Gang Li Chengxiang Wang National Mobile Communications research Laboratory School of Information Science and EngineeringSoutheast UniversityNanjing 211189China School of Internet of Things Engineering Jiangnan UniversityWuxi 214122China Pervasive Communication research Center Purple Mountain LaboratoriesNanjing 211111China

In this paper,the channel impulse response matrix(CIrM)can be expressed as a sum of couplings between the steering vectors at the base station(BS)and the eigenbases at the mobile station(MS).Nakagami distribution was used to describe the fading of the coupling between the steering vectors and the *** measurements were carried out to evaluate the performance of this proposed ***,the physical implications of this model were illustrated and the capacities are *** addition,the azimuthal power spectrum(APS)of several models was ***,the channel hardening effect was simulated and *** showed that the proposed model provides a better fit to the measured results than the other CBSM,i.e.,Weichselberger ***,the proposed model can provide better tradeoff between accuracy and complexity in channel *** CIrM model can be used for massive MIMO design in the future communication system design.

关键词： CBSM channel capacity channel hardening channel modeling massive MIMO

An Accurate and Safe Small raman Gain Measurement for Installed Fiber Optic Cables

在线全文

学校读者我要写书评

暂无评论

光学学报 2003年第S1期23卷 571-572页

作者： Takayuki Miyakawa Yasuyuki Nagao kddi r&d laboratories Inc. 2-1-15 Ohara Kamifukuoka-shi Saitama JapanKDDI R&D Laboratories Inc. 2-1-15 Ohara Kamifukuoka-shi Saitama Japan

Novel small raman gain measurement method for installed fiber optic cables using a modulated pump light is proposed. We have demonstrated accurate raman gain measurement in small raman gain less than 1dB and we also m... 详细信息

关键词： for in as In be An Accurate and Safe Small raman Gain Measurement for Installed Fiber Optic Cables FrA of

Neutralization of SArS-CoV-2 infection by antibodies targeting diverse epitopes

在线全文

学校读者我要写书评

暂无评论

Genes & diseases 2024年第4期11卷 134-137页

作者： Shusheng Wang Yunji Liao Kaiyong Yang Hang Ma Zhangyi Song Haiqiu Huang Li Zhang Ailing Wang Lei Han Jiawei Zhang Hui Chen Haiyang Yin Yantin Bian Hua Jiang Xiaodong Xiao Yueqing Xie Yunsheng Yuan Jianwei Zhu Engineering research Center of Cell and Therapeutic Antibody Ministry of EducationSchool of PharmacyShanghai Jiao Tong UniversityShanghai 200240China Jecho laboratories Inc.FrederickMD 21704USA Jecho Institute Co. Ltd.Shanghai 200240China

The CoVId-19 pandemic that started in late 2019 is sweeping through the world,posing historic challenges to global health,and disrupting social and economic *** and recent studies indicate that monoclonal antibodies can be efficacious in preventing and treating SArSCoV-1 and SArS-CoV-2 *** a phage display platform,we have identified dozens of monoclonal antibodies that bind to diverse epitope groups on the SArS-CoV-2 spike *** of them bound to the receptor binding domain(rBd)and inhibited ACE2-rBd interaction.

关键词： antibodies inhibited monoclonal